CEDEMERID^ OF BOREAL AMERICA. 409 



without an examination of its head and mandibles, it might 

 be mistaken for that species. The only variation observed 

 is in the color of the elytra, which may be black or blue, 

 with an intermediate bronze. 



While there is a possibility of doubt as to the correct- 

 ness of its reference to Chrysanthia, I can find nothing 

 in the descriptions of the latter to warrant any other 

 course. 



Specimens are known to me from the District of Co- 

 lumbia, Florida, Texas, and Arizona (Yuma). 



Sisenes Champion. 



Form slender, somewhat recalling Lycida?. Head 

 moderately elongate. Eyes oblique, scarcely emarginate. 

 Antenna? slender, eleven-jointed, inserted at a distance 

 from the eyes. Mandibles bifid at tip. Terminal joint 

 of maxillary palpus elongate-oval. Tibia? with two ter- 

 minal spurs. Claws simple. 



One species is known to me in our fauna, and I have 

 no doubt of the correctness of its association with Sisenes, 

 but it possesses certain peculiarities which seem not to 

 belong to the other species. The head is certainly more 

 prolonged than the figures of Mr. Champion's species 

 indicate, and his description merely says " a little pro- 

 longed." The antenna? are distant at base from the eyes, 

 more so than in any species I have seen, excepting Rhi- 

 noplatia. 



This insect seems to illustrate fully the difficulties en- 

 countered, even in a limited fauna like our own, in en- 

 deavoring to arrive at some proper understanding of the 

 limits of the genera. In other words, this species seems 

 to bear the same relationship to the others that the species 

 I have called Chrysanthia refanda bears to Copidita 

 ihoracica. 



Proc. Cal. Acad. Sci., 2d Ser., Vol. VI. ( 29 ) September 27, 1890. 



